Computer study of the Raman spectra and infrared optical properties of gallium nitride and gallium arsenic nanoparticles with SiO2 core and shell
J Nanopart Res (2014) Vol.16, P.2351(1-18)
Alexander Y. Galashev
Abstract The J(ω) Raman spectra of the (GaN)129, (SiO2)86, and (GaN)54(SiO2)50 nanoparticles as well as the optical properties of silicon dioxide and gallium arsenide nanoparticles and the four-component particles based on them were calculated using the molecular dynamics method. The spectrum of (SiO2)86 had three broad bands only, whereas the Raman spectrum of (GaN)129 contained a large number of overlapping bands. The shape of Raman spectra for four-component particles depends strongly on the way the GaN-, GaAs-, and SiO2-components are located in the nanoparticle. Increasing the temperature (from 300 K upto 1500 K) of nanoparticles causes a significant rise in the intensity of the Raman spectrum. Thus, the odd J(ω)-spectrum peaks for the nanoparticle with the SiO2-core shift in opposite directions, but this heating does not lead to the shift of J(ω)-spectrum peaks for the (GaAs)54(SiO2)50 nanoparticle with SiO2-coating. The refractive index and absorption coefficient as well as the number of optically active electrons depend weakly on the arrangement of the conductor (GaAs) and isolator (SiO2) in the nanoparticle.